A rough flu season could compound the problems the COVID-19 pandemic has already caused in the United States, and public health experts are warning that a mild flu season in the Southern hemisphere may not mean Americans will experience the same thing.
The U.S. hasn’t been as aggressive in maintaining steps to mitigate the spread of the coronavirus, which had the bonus effect of limiting the spread of flu in the countries that did.
“There is some false sense of security,” Lavanya Vasudevan, a Duke University community and family health professor, said on a call with reporters last week.
So there is a strong push this year for people to get a flu vaccine, one tool available to combat flu that doesn't yet exist for COVID-19.
“The stakes are just much higher because we’re risking a twindemic,” Vasudevan said.
The U.S. looks to several countries as it plans for flu season here. Australia, Chile and South Africa all had low activity, according to a Centers for Disease Control and Prevention report issued last week. It also noted how the median number of weekly flu cases in the U.S. decreased by around 61 percent starting in March compared to earlier in the winter and fall, after people started staying home because of the pandemic.
The measures imposed to prevent COVID-19 — like mask-wearing and social distancing — helped prevent the flu from spreading then.
But the U.S. is rolling back social distancing measures, and was never performing as well as a country like Australia in that regard. The U.S. is about 13 times larger than Australia in population, but during coronavirus peaks that both countries experienced in July, the U.S. had around 100 times more cases per day, according to data from Johns Hopkins University’s coronavirus resource center.
Australia has had 854 deaths total. The U.S. had nearly 800 deaths per day on average last week and reached a milestone of 200,000 deaths on Tuesday.
That’s why experts worry the U.S. might not replicate the flu season success seen in other countries.
“Those countries really enforced social distancing. There was really good mask-wearing. We really haven’t seen that in the U.S.," Vasudevan said. "We’ve done really poorly in terms of implementing some of those safety measures.”
The flu season by itself is a significant burden on the health system every year, says Andrew Pekosz, a Johns Hopkins University virologist. This year, it could have an effect on the nation’s lab testing infrastructure, which is already under strain because of COVID-19. Because the infections caused by flu and coronavirus cause similar respiratory symptoms, people with flu might think they have COVID-19 and seek out that test, or vice versa.
He said lab testing companies and individual labs are developing tests that can diagnose both infections at once, but said those tests are not yet widely available. Health providers will likely have to make choices based on scarce resources.
“Will you be testing for both anytime someone comes in complaining of respiratory symptoms? Will you prioritize one versus the other? Will you prioritize COVID-19 because we know that it could be more dangerous for certain groups? These are questions that most medical institutions are grappling with right now,” he said on a call with reporters Tuesday.
U.S. health officials appear cognizant of the risks, and are pushing for Americans to get their flu vaccines this year.
“With both COVID-19 and the flu circulating this fall, this will be in my opinion the most important flu season of our lifetimes,” Surgeon General Jerome Adams told senators at a Health, Education, Labor and Pensions Committee hearing earlier this month. “Less flu and fewer hospitalizations will help conserve precious health care resources.”
The CDC estimates that manufacturers will produce more vaccines this year than ever, making up to 194 to198 million doses available, compared to 175 million during the 2019-2020 flu season. The agency is dramatically increasing the amount of doses it purchases for adults, buying 9 million this season compared to 500,000 in normal years.
But Vasudevan and others fear there could be fewer people seeking vaccinations this year as more people are skipping routine care. Even in a normal year, only half of the adult population gets a flu vaccine. During the 2018-19 season, around 45 percent of adults got flu shots, according to the CDC. A year earlier, it was just 39 percent.
Many employees get their flu shot at their work offices. But this year with more people working from home, it creates one more potential step that could get in the way of being vaccinated.
Mark McClellan, a former head of the Food and Drug Administration and the Centers for Medicare and Medicaid Services, said that more distribution methods will be needed in order for flu vaccine rates to go up. He said that this year’s flu vaccination campaign will also be an important test of how effectively the U.S. can vaccinate against COVID-19 once a vaccine is available, likely later this year and on a more widespread basis next year.
“If we can get vaccination right for flu, that’s a great practice, great warmup for doing an effective job on the challenges ahead with a COVID vaccine,” McClellan, who now leads the Duke-Margolis Center for Health Policy, said last week.
It will also take better public health messaging if public health leaders want more people vaccinated this year, says Daniel Salmon, director of Johns Hopkins’ Institute for Vaccine Safety.
He said that normally, public health messaging needs to adapt a message for a specific audience, and that people have a wide range of views about vaccines that need to be addressed specifically. But in the case of this year’s flu season, he said, a singular “campaign that really emphasizes the community benefit of getting flu vaccine” might be appropriate.
“That’s a message that should resonate with everyone, and given where we are at this moment in history, that would be a really good use of time and resources,” he said on Tuesday’s call.